I have used the Fox body A pillar gauge pods on various 71-2-3 Sportsroofs with excellent results. Only very slight and simple tweaking with a heat gun is needed for near perfect fit onto the existing a factory pillar.
To preserve the factory plastic A pillar trim I use Black silicone seal to adhere the pod to the factory pillar trim. Thus no screws needed that would otherwise damage rare factory trim parts. All wiring can be run out the very bottom of the pod and snaked thru between the A pillar and dash pad, thus negating the need for any drilling and keeping the wiring pretty much invisible.
For me, the three pod version "intruded" a bit too much upon my entry/exit; in addition, the top gauge on the 3 pod was uncomfortably "right in your face". All subjective stuff of course.
One and two gauge pods presented no such issues in my opinion.
Attached is my current gauge setup for your review:
